I have a feeling that ultimately the tour will dissapear eventually, i think it's just too much in the way in it's current location. A tunnel wouldn't be very realistic, a bridge is possible but not very propable i guess, wouldn't it be problematic driving the long tram in the small turn heading to the Ring of Fire part and going on the bridge? Maybe just close it down to give it a place further back in the park after future expansions? A bit like the location the ride has at WDW.